“
”
“We provide personal
customer support through
training and education
programs, a telephone
hotline and technical field
assistance, as well as one of
the best warranty programs
in the business.”
Peter H. Sheppard
President
M-Series Power Steering Service Manual
Part # 1000400 REV. A
Index
SECTION
DESCRIPTION
PAGE
I
SAFETY NOTICE..........................................................................................2
Introduction ....................................................................................................3
Oil Flow ..........................................................................................................5
Gear Identification ..........................................................................................6
Exploded View of Steering Gear....................................................................7
Service Parts Kits/Lubrication........................................................................8
II
DIAGNOSIS & TROUBLESHOOTING......................................................9
Glossary..........................................................................................................14
Troubleshooting Guide ..............................................................................15-18
III
COMMON PROCEDURES ........................................................................19
Preventive Maintenance ................................................................................ 20
Input Shaft Seal Replacement ...................................................................... 22
Sector Shaft Seal Replacement .................................................................... 30
Bleeding Single Gear ....................................................................................28
Bleeding Dual Steering Gears ......................................................................29
Axle Stop Adjustment....................................................................................32
Alternate Bleed Procedure ............................................................................33
Set Relief Plungers Manual Plungers Adjustment ...................................... 42
Set Automatic Relief Plungers ......................................................................35
Adjust Automatic Relief Plungers ................................................................ 36
Repair Automatic Relief Plungers ................................................................37
Pitman Arm Removal ....................................................................................41
Pitman Arm Installation ................................................................................43
Input Shaft Seal Replacement (M-110P2)....................................................45
IV
DISASSEMBLY............................................................................................49
VI
REASSEMBLY ............................................................................................55
VII
DUAL STEERING SYSTEMS ....................................................................61
VIII
FINAL ADJUSTMENTS..............................................................................65
IX
MISCELLANEOUS......................................................................................66
Troubleshooting Checklist ............................................................................66
Order Sheet - Heavy Duty Power Steering Test Kit ....................................67
1
SAFETY NOTICE
STOP! Before you begin, please read this manual carefully. The repair procedures outlined in this manual are
for repairing the Sheppard Integral Power Steering Gear. To ensure safe and reliable operation, these service and repair
procedures must be followed carefully.
WARNING
THIS MANUAL CONTAINS A NUMBER OF SAFETY SIGNAL WORDS LIKE: DANGER, WARNING, CAUTION, IMPORTANT, or NOTE. The information following a safety signal word is very important.
DANGER it means the information will help you avoid an extreme hazard that could kill or
When you see the word
cause a very serious injury every time.
When you see the word WARNING it means there is a hazard that is not as serious as DANGER but the hazard could
cause injury or death if you do not follow the proper rules or procedures.
When you see the
CAUTION it means the information that follows will help avoid damage to the steering gear.
The signal words IMPORTANT or NOTE are used to draw attention to ways of doing your job better or right.
2
INTRODUCTION
This service manual covers repair procedures for the Sheppard steering gear assembly only. The Vehicle
Manufacturer’s Service Manual should be used for removal and reinstallation instructions, and hydraulic supply pump
specifications.
Any reference made to a brand name, special tools or item part number are made as a guide.
All information, illustrations and specifications in this manual are the latest available at the time of printing. We
reserve the right to make changes without notice. If you are not certain you have the current revision of this manual
or if you have questions about procedures, please call our Field Service Department at 717-633-4111 before you
begin repairs.
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OPERATING PRINCIPLES
The Sheppard M-Series Integral Power Steering Gear provides full-time hydraulic steering. Only enough manual
effort to overcome the torsion bar and turn the rotary valve is required.
The actuating shaft (1) is connected to the steering column and is centered within the rotary valve by a torsion bar.
The rotary valve shaft is threaded into the piston with ball threads (2) and travels within the piston on steel balls.
Rotating the input shaft causes high pressure fluid to build up on one end of the piston. This higher pressure causes
the piston to move in the bore of the gear housing. The sector shaft (3) is engaged to a rack gear (4) machined into
one side of the piston. Piston rack movement causes sector shaft and pitman arm rotation. When steering shaft
rotation stops, the actuating valve returns to its neutral position. Relief valve plungers or adjustable stops are used
in the bearing cap and cylinder head. When the plungers are adjusted properly, they will unload the hydraulic
system if the wheels are in a full turn to either direction.
TORSION BAR
(2) ROTARY VALVE SHAFT BALL THREAD
CYLINDER HEAD
BEARING CAP
RELIEF PLUNGER
(1) ACTUATING
SHAFT
(4) PISTON RACK
(5) PISTON RING
(3) SECTOR SHAFT
When the engine is running there is constant low pressure oil flow through the steering gear. This constant oil flow
provides an instant response and absorbs road shock to help eliminate steering wheel kick. Pressure is equal
throughout the steering gear; however, care should be used when towing or moving a vehicle where the engine or
hydraulic supply pump is not running.
NOTE:
If sudden loss of pressure occurs during normal driving, the parts are designed to
provide mechanical back-up steering so that the vehicle may be safely steered to the side
of the road.
An optional integral pressure relief valve is available on the M-Series Steering Gears. This valve limits maximum
steering system relief pressure at the steering gear. This reduces system temperature by avoiding high pressure
by-pass and recirculation within the pump.
The Sheppard Integral Power Steering Gears have been designed to provide long service life and simple service
repair. The rack and sector shaft does not require center point adjustment. The clearance between the cylinder bore
and the piston is closely controlled, and a piston ring (5) was added to better use the hydraulic oil supplied.
With reasonable care and limited maintenance the Sheppard M-Series Steering Gear will provide many miles of
reliable performance.
4
OIL FLOW THROUGH THE M-SERIES GEAR
Figure 1
Here we see the steering gear in the neutral or non steering position. Equal low pressure is being applied to
both ends of the steering gear piston. The oil is circulating at back pressure only and provides a hydraulic cushion for the steering gear. All oil is being circulated
through the steering gear and back to the reservoir to
help cool the system.
Figure 1
Figure 2
When the steering wheel is turned, the actuating valve is
opened in one direction, all pressurized oil is applied to
one end of the steering gear piston. This pressure build
up causes the piston to move in the steering gear.
Figure shows all oil being distributed to the input end of
the gear.
Figure 2
Figure 3
Figure shows all oil being distributed to the cylinder
head end of the gear.
Figure 3
When no input is applied through the steering wheel the gear returns to the neutral or non steering position.
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STEERING GEAR IDENTIFICATION
A number is cast into the steering gear housing and identifies the basic family the steering gear belongs to.
Stamped letters and numbers on an exposed machined surface of the housing (opposite the mounting side) identifies
the gear specification; see gear P/N chart below. In the above example the complete identification is Model M100PAD1A1. Cast number M-100 would refer to the M-Series steering gear family.
GEAR P/N CHART
M-100
P
H
B1
SERIES GEAR
(REVISION LEVEL)
MODEL NUMBER ALPHABETICALLY
POWER
GEAR SIZE
A serial number is also assigned to each steering gear and
is interpreted below:
➔
00
C
15914
2000
(Used Last
Two No’s)
MO.
Built
A-Jan
B-Feb.
C-Mar.
Etc.
Sheppard
Ref.
Only
THIS SERIAL NO. IS 00C15914
6
➔
➔
SERIAL NUMBER SYSTEM
REPRESENTS:
(00) YEAR BUILT – 2000
(C MONTH – MARCH
(15914) REF. ONLY
7
8
9
10
11
12
13
14
5
6
3
4
1
2
SERVICE PARTS LIST
HOUSING (NOT SOLD SEPARATELY)
CYLINDER HEAD (NOT SOLD
SEPARATELY)
BEARING CAP/SHAFT ASSEMBLY
SECTOR SHAFT COVER (NOT SOLD
SEPARATELY)
SECTOR SHAFT
PISTON ASSEMBLY (NOT SOLD
SEPARATELY)
PRESSURE RELIEF CARTRIDGE
PITMAN ARM RETAINER
PITMAN ARM (SOLD BY APPLICATION)
INPUT SHAFT SEAL KIT
SECTOR SHAFT SEAL KIT
CYLINDER HEAD PLUNGER KIT
BEARING CAP PLUNGER KIT
BLEEDER PLUG KIT
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SEAL KITS
M100 COMPLETE SEAL KITS:
Sheppard Part No. 5543211
Complete seal kit for all M100 steering gears with push-on dust boot
on sector shaft
Sheppard Part No. 5542331
Complete seal kit for all M100 steering gears with a pressed-in excluder
seal on the sector shaft
Sheppard Part No. 5543481
Complete seal kit for all M100 steering gears with a snap-ring cover and
a push-on dust boot at the sector shaft
Sheppard Part No. 5543491
Complete seal kit for all M100 steering gears with a snap ring cover and
a pressed-in excluder seal on the sector shaft
M90 COMPLETE SEAL KIT
Sheppard Part No.
5543551Complete seal kit for all M90 steering gears
M80 COMPLETE SEAL KITS:
Sheppard Part No. 5543461
Complete seal kit for all M80 steering gears
M110 COMPLETE SEAL KITS:
Sheppard Part No. 5541411
Complete seal kit for all M110P2 steering gears
Sheppard Part No. 5542621
Complete seal kit for all M110P1 steering gears
M-SERIES INPUT SHAFT SEAL KITS:
Sheppard Part No. 5542261
Input shaft seals for all M-Series gears built from June 1991 to present
Sheppard Part No. 5541351B
Input shaft seals for all M-Series gears built prior to June 1991
M100 SECTOR SHAFT SEAL KITS:
Sheppard Part No. 5542271
Sector shaft seals for all M100 steering gears with a pressed-in excluder
seal at the sector shaft with bolt on case
Sheppard Part No. 5543601
Sector shaft seals for all M100 steering gears with a push-on dust boot
at the sector shaft and a snap ring cover
Sheppard Part No. 5543591
Sector shaft seals for all M100 steering gears with a pressed-in excluder
seal at the sector shaft and a snap ring cover
Lubrication - Steering Gears
FLUID RECOMMENDATIONS
The lubricant used in the power steering system lubricates moving parts and removes heat. Too much heat reduces
efficiency and increases wear. It is important to use the lubricant specified by the Vehicle Manufacturer and
approved by the R. H. Sheppard Co., Inc.
R. H. Sheppard Co., Inc. approves the use of the following fluids in the M-Series steering gear:
R. H. Sheppard Company Approved Fluids for Power Steering
Automatic Transmission Fluid Dexron III
Automatic Transmission Fluid Type “E” or “F”
Castrol Supreme XHD 15W40
Castrol MP Dexron III/Mercon
Castrol TransSynd
Chevron Delo 400 Multigrade 15W40
Chevron Dexron III/Mercon
Chevron RPM Heavy Duty Motor Oils 15W40
Chevron 10W40 Supreme
Cummins Premium Blue 2000 15W40
ELF Lubricants XT2388 / Dexron III
Exxon Auto H32 Hydraulic Fluid
8 Exxon Firexx HF-DU68
Fleetrite PSF (CH990625)
Ford Spec. M2C138CJ
Mack EOM Plus
Mobil 1 0W30 Tri-Synthetic
Mobil 1 15W50 Motor Oil
Mobil ATF 210
Mobil Quintolubric 822-220
Mobil Super 10W40 Motor Oil
Mobil Super 15W40 Motor Oil
Shell Rimula Premium 15W40
Shell Rotella T30W
Shell Rotella T SAE 30
Shell Rotella T 15W40
Shell Tellus T46 Oil
Texaco 10W40
Texaco Code 1831 Power Steering Fluid 11872
Texaco Code 1854 Mercon / Dexron III
Texaco Texamatic 7045E Automatic Transmission Fluid
Texaco URSA 15W40 code 2109
Union 10W40
Union 15W40
Unocal 46 Power Steering Fluids
Unocal Guardol 15W40 Motor Oil
US Oil Wide Range Automatic Transmission Fluid
Valvoline All-Climate 10W40 Motor Oil
Valvoline AW 32 HVI Oil
DIAGNOSIS & TROUBLESHOOTING
This section of the manual is designed to help the mechanic troubleshoot steering complaints. Used
properly the section will assist you in completing a proper and less time consuming diagnosis and repair.
You will find sub sections covering diagnosis, troubleshooting, definitions and terms for complaints.
To properly repair the problem you must have a clear understanding of the driver’s complaint.
The Glossary of Terms and Definitions will help pin point the problem quickly.
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Locate the complaint in the troubleshooting section and complete all the necessary tests as outlined in
the proper section of this manual. Complete the troubleshooting checklist and record your findings.
If after completing the diagnosis and repairs found in the Diagnosis and Troubleshooting section of this
manual, you are unsure of your findings, contact the Field Service Department of the R. H. Sheppard
Co., Inc. at 717-633-4111. When contacting the R. H. Sheppard Co. with a problem be sure to have
your completed troubleshooting checklist available.
Do not remove the gear until you have completed all procedures to solve your problems. Remember the
steering gear is only one part of a total steering system. Many factors outside the steering gear will
affect steering performance.
9
DIAGNOSIS AND TROUBLESHOOTING
IMPORTANT: Do Not Remove The Steering Gear From The Vehicle
To properly diagnose steering complaints it is important to understand the complete steering system. Many factors
outside of the steering system will affect steering performance. Factors such as misalignment, looseness in front end
components, mismatched tires and dry fifth wheel, to name a few, will affect steering.
A trouble shooting checklist is provided in the Miscellaneous Section of this manual. This form can be removed and
photo copied. This checklist will follow the diagnosis outline below.
GENERAL DIAGNOSIS
Many times a steering gear is removed and disassembled needlessly because an orderly diagnostic procedure is not
followed.
A glossary of common terms is provided at the end of this section of the manual. This glossary is intended to help
you better understand the problem.
Begin your diagnosis using the following outline as a guide.
I.
DEFINE THE COMPLAINT
a. Talk to and question the driver - Refer to the glossary to obtain a clear understanding of what the
driver is saying.
b. Drive the vehicle - If possible have the driver show you what he is experiencing. Drive the
vehicle together to duplicate the condition.
II.
PERFORM A VISUAL INSPECTION OF THE VEHICLE
a. Check for dry fifth wheel - Lack of lubrication will tend to steer the vehicle.
b. Check tires for mismatch, improper inflation or uneven wear patterns.
c. Check for poor loading practices - Special body or equipment installations should be checked for
their effect on steering performance.
d. Check for suspension sagging or shifting - Out of line rear axles will tend to steer the front end
of the vehicle.
III.
INSPECT MECHANICAL COMPONENTS
a. Check all front axle components for wear, looseness or seizing.
b. Inspect steering column for drag - more than 10 inch pounds of drag measured with the column
suspended at the angle of operation is excessive.
c. Check steering gear mounting to be sure that it is tight. A steering gear that is shifting on the
frame will affect steering performance.
IV.
CHECK THE HYDRAULIC SUPPLY SYSTEM
a. Follow the procedures as outlined in the hydraulic diagnosis section of this manual. Oil
pressure and flow must be within the vehicle manufacturer’s specifications.
HYDRAULIC DIAGNOSIS
The Sheppard M-Series integral power steering gear is a reactionary part of the power steering system. By
reactionary we mean that its operation is dependent on the proper supply of oil pressure and flow from the hydraulic
supply pump.
10
When the steering wheel is turned, oil flow is applied to one end of the steering gear piston causing pressure to build.
This pressure causes the piston to move. As the piston moves it is displaced by a volume of oil under pressure. The
speed the piston moves is dependent on the amount of oil flow or,
Flow = Speed of steering.
Maximum system relief pressure limits the amount of steering gear output available to steer your specific vehicle or,
Pressure = The amount of work the steering gear can do.
Keeping the basic formula of “Flow = Steering Wheel Speed” and “Pressure = Work” in mind will help you diagnose
steering problems.
Oil pressure and flow requirements are set during the design of the steering system. When diagnosing steering
problems, oil pressure and flow must meet design specifications. Pressure and flow specifications vary. Follow the
vehicle manufacturer’s recommendations.
System back pressure and operating temperature must be considered during the diagnosis of the steering system.
High system back pressure will create heat.
High system oil temperatures reduce overall efficiency of the steering pump and steering gear.
Various types of pressure and flow meters are available to diagnose power steering problems. A pressure gauge rated
at 3000 PSI and a flow meter with a capacity of 10 GPM are needed to check oil pressure and flow.
A shutoff valve placed downstream from the pressure gauge allows the hydraulic supply pump to be isolated from the
gear to check pump relief pressure. A simple thermometer placed in the reservoir will show system temperature.
Pictured below is the Sheppard Heavy Duty Power Steering Test Kit Part #5517641. This is an excellent tool for
troubleshooting power steering systems and can be ordered using the form in the Miscellaneous section of this
manual.
This tester is a self contained, direct
reading device to check system flow,
pressure or both at the same time. It
can detect worn components, check
flow and pressure control settings or
monitor overall system performance.
LOW COST - EASY TO USE
Only one hose connection is broken,
either at the pump output or at the
pressure input to the power steering
gear housing.
* Installs between pump and steering gear
* Shutoff valve isolates pump from gear
* Pressure and flow can be read at the same time
* 0-3000 P.S.I. pressure gauge
* 1-10 G.P.M. flow meter
* Complete with hoses & standard swivel fitting
WARNING
OIL UNDER
PRESSURE
CAN PENETRATE THE SKIN
CAUSING SEVERE INJURY.
NEVER USE YOUR HANDS
TO CHECK FOR LEAKS
Using a pressure and flow test kit, proceed with the evaluation of the hydraulic system. Record your findings on the
trouble shooting checklist.
11
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NOTE: All tests must be performed with the vehicle parked on a clean, dry, solid surface, with the engine
running and the full weight of the vehicle on the front wheels.
1.
Connect the pressure and flow tester in series with the pressure line of the pump. Make a copy of the
trouble shooting test sheet.
2.
Start the engine and check system oil level. Make sure the oil is flowing in the proper direction as indicated
by the arrow on the flow meter.
3.
Place a thermometer in the reservoir.
4.
Run the engine at idle speed. Slowly close the shut off valve until you have a pressure reading of 1000
PSI. Maintain this pressure until system temperature reaches 180 degrees Fahrenheit. Open the shutoff
valve all the way when the temperature is 180 degrees.
5.
Check System Backpressure:
Normal system back pressure will be between 0 and 100 PSI with the engine idling and the steering wheel
stationary. Dual systems will normally read slightly higher. Back pressure should be checked at normal
operating temperature.
6.
Pump Maximum Relief Pressure:
With the engine running at specified idle speed, slowly turn the shutoff valve until it is closed and read the
pressure at which the pressure relief valve opens. (Open the shutoff valve as quickly as possible to avoid
heat build-up or possible damage to the steering pump.) This pressure reading should equal the maximum
pump pressure specified by the vehicle manufacturer. Check specifications.
A BAD PRESSURE RELIEF VALVE MAY NOT RELIEVE PUMP PRESSURE. CLOSING THE SHUTOFF
VALVE MAY CAUSE SEVERE PUMP DAMAGE OR HIGH-PRESSURE HOSES TO RUPTURE. WATCH
THE PRESSURE GAUGE CLOSELY. IF PRESSURE RISES RAPIDLY OR GOES ABOVE 2500 PSI. STOP!
DO NOT CLOSE THE VALVE ALL THE WAY.
WARNING
SOME STEERING PUMPS ARE NOT EQUIPPED WITH INTEGRAL RELIEF VALVES. CLOSE THE SHUTOFF VALVE SLOWLY AND WATCH THE PRESSURE. IF SYSTEM PRESSURE GOES ABOVE 2500 PSI DO NOT CONTINUE TO CLOSE THE
SHUTOFF VALVE. PUMP DAMAGE OR PERSONAL INJURY MAY RESULT.
7.
Flow Test:
Measure oil flow under the following conditions. Record your findings on the Trouble Shooting Checklist.
Flow at idle with back pressure only
Flow at idle under a 1500 PSI load applied with the shutoff valve
Flow at full governed RPM with back pressure only
Flow at full governed RPM under a 1500 PSI load applied with the shutoff valve
8.
Aerated Oil:
Visually check for air mixed with the oil in the steering system. The oil should be clear. Any signs of
frothing indicates air in the system and steering performance will be affected. Carefully check for leakage
on the suction side of the steering pump. Drain, refill, and bleed the system. Follow the procedure for
setting relief plungers in the “Common Procedures” section of this manual.
Before any steering gear repairs are made complete the hydraulic supply evaluation
and make any repairs. Many times steering gears have been repaired or replaced needlessly because a
hydraulic supply system evaluation had not been made.
Additional references to pressure and flow testing will be made in the diagnosis charts in the
“General Diagnosis” section of this manual.
9.
12
Dry park Pressure and Input Effort:
Measure and record the pressure required to steer the vehicle from full left to full right while parked. Input
effort is measured at the steering wheel retaining nut. Use a dial type inch pound torque wrench to check
static steering input effort. Normal Input effort will be less than 100 inch pounds.
OIL FLOW AND PRESSURE RECOMMENDATIONS
The Sheppard M-Series power steering gears are designed to operate at a maximum pressure of 2175 PSI. Each
vehicle Manufacturer specifies the maximum operating pressure at which their various steering installations are to be
operated. Always refer to your Vehicle Manufacturer’s specifications for the correct pump relief settings for the vehicle you are working on.
WARNING
DO NOT INCREASE THE MAXIMUM OPERATING PRESSURE WITHOUT CONSULTING THE
VEHICLE MANUFACTURER. SERIOUS DAMAGES MAY OCCUR.
Oil flow and pressure for the Sheppard M-Series steering gears are outlined below by model number. Refer to the
gear identification section of this manual to determine the model of steering gear you are working on. Oil flow
requirements remain the same for all similar models and do not change from installation to installation. Follow the
Vehicle Manufacturer’s recommendation.
M-SERIES STEERING GEARS
M80P
M90P
M100P
M110P
RATED PRESSURE
2175 PSI
2175 PSI
2175 PSI
2175 PSI
MIN. PUMP FLOW (SINGLE)
2.1 GPM
2.5 GPM
3.0 GPM
3.5 GPM
2.5-6.0 GPM
2.5-6.0 GPM
3.0-6.0 GPM
3.5-6.0GPM
N/A
4.6-6.0 GPM
5.1-6.0 GPM
5.6-6.0 GPM
16.8-1
18.9-1
18.9-1
23-1
1.75 IN.
2.0 IN.
2.0 IN.
2.25 IN.
PUMP FLOW RANGE (SINGLE)
PUMP FLOW RANGE (DUAL SYSTEM)
RATIO
OUTPUT SHAFT DIAMETER
Before any steering gear repairs are made complete the entire troubleshooting checklist provided in this manual.
Many times steering gears are removed or replaced needlessly. Remember, once the steering gear is removed there is
only one thing that can be determined -its weight!!!
If you have completed the troubleshooting checklist and are unsure of your diagnosis contact your Vehicle
Manufacture representative, or the Field Service Department of the R. H. Sheppard Co., Inc. at 800-274-7437.
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GLOSSARY
1. Rotary Valve - Internal valve in the bearing cap of the steering gear. It is actuated by the steering wheel through
the yoke connection of the steering column.
2. Back Pressure - Circulating pressure of the steering system.
3. Base Mounted Gear - The steering gear is mounted to the frame rail or bracket utilizing the eight mounting
holes opposite the sector shaft cover.
4. Bearing Cap - End cap of the steering gear that houses the actuating shaft and valve.
5. Bearing Cap Cover - Small cover on the end of the bearing cap of the steering gear. The bearing cap cover
houses the input shaft oil and salt seal.
6. Bleeder Screw - 1/8” allen screw located in the sector shaft bore of the steering gear.
7. Cavitation - Bubbles that form in the oil which keep the pump from supplying pressure and volume.
8. Contamination - Dirt or other foreign material in a fluid.
9. Cylinder Bore - Long bore of the steering gear where the steering gear piston is housed.
10. Cylinder Head - The end cap of the steering gear bolted on the housing opposite the actuating shaft end of the
gear.
11. Displacement - The volume of fluid that can pass through a pump or cylinder in a single revolution or stroke.
12. Feedback - A transfer energy from the output of a device to it’s input.
13. Fluid Flow - The stream or movement of a fluid, or the rate of it’s movement.
14. Piston - Is found in the cylinder bore. Changes the hydraulic force to mechanical force in the steering gear.
15. Plunger - Relief valves in the steering gear to limit steering gear piston travel. Plungers are adjustable and can
can be either manual or automatic adjusting.
16. Pressure Relief Valve - Optional pressure relief valve integral to the steering gear to limit system operating
pressure. Identified by a large hex nut on the side of the bearing cap.
17. Pump - A device that converts mechanical force and motion into hydraulic fluid power.
18. Rack Teeth - The area on the piston that engages the sector shaft teeth.
19. Recirculation Ball Thread - The area of the rotary valve on which the 24 steel balls travel.
20. Relief Valve - A pressure control valve used to limit system pressure.
21. Sector Shaft - The shaft the pitman arm is attached to.
22. Sector Shaft Bore - Area of the steering gear that houses the sector shaft.
23. Slave Gear - Right hand gear in a dual system application.
24. Slave Ports - Threaded openings in the cylinder head, bearing cap and sector shaft bore to install the pressure
lines to operate the slave gear.
25. Tab - Lock Retainer - Bolt assembly used to provide initial torque when installing the pitman arm. Uses
alignment tabs that fit into the pitman arm and restraining tabs to be locked into the head of the retainer.
26. Flow - The amount of fluid that passes a certain point in a unit of time. The volume of flow is usually expressed
in gallons per minute for liquids.
14
TROUBLESHOOTING GUIDE
This section is designed to give you causes and possible remedies for the most common problems.
Symptom
Possible cause
Remedy
Oil leaking at output shaft
of steering gear.
Damaged sector shaft seal
Replace sector shaft seal and
sector shaft if necessary
Oil leaking at actuating
shaft of steering gear
Worn or damaged oil seal
Replace actuating shaft seal
Oil leaking at supply pump
drive shaft
Damaged oil seal
Oil seal heat damaged
Loose or damaged bushing
on pump drive shaft
Replace oil seal
Check operating temperature
Repair pump per pump
service instruction
Lubricant milky or white in
appearance
Water entry through
reservoir venting system
Clean vent system or
replace cap assembly
Flush System
Oil forced out of reservoir
or foaming
Clogged oil filter
Change oil and oil filter
Change more often
Air in system
Bleed air from system
Check for air leak on
suction side of supply pump
Relief plungers of steering
gear not adjusted properly
creating high operating
temperatures
Adjust relief plungers
(See Common Procedures)
Air leak in suction side of
supply pump
Refer to pump servicing
instructions
Pump cavitating
Check for restriction in
pump supply
Oil overheating
Check for restriction in
steering gear return
Faulty seal at pump drive
shaft
Repair pump
Faulty seal at accessory
shaft driving supply pump
Repair accessory drive
Operating temperatures too
high
Check and correct cause of
overheating
Change intervals too long
Incorrect lubricant used
Change oil more often
Drain, flush and refill with
recommended fluid
Oil flow restriction
Check back pressure
Oil flow too high
Check maximum oil flow
Engine oil in power steering
reservoir (Gear driven pump)
Lubrication oil discolored
High operating
temperatures
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Symptom
Remedy
No power steering on cold
starting
Hydraulic supply pump
vanes not extending
(Vane type pump only)
Increase engine speed
momentarily to extend
vanes and start pump
action.
Usually does not happen
often and does not last
long. Not a cause for pump
repair or replacement.
Excessive pump pressure
with steering gear in neutral
position.
Pinched oil return line
High back pressure
Relocate line
Binding steering column
Repair steering column
Wheel cuts restricted
Relief plungers not adjusted
properly
Adjust relief plungers
Erratic steering or
mechanical steering only
Insufficient volume of oil
Refer to pump servicing
instructions
Sticking pressure relief
valve in steering gear
Replace relief
valve as required
Faulty supply pump
Check pump flow
Steering out of alignment
Align front end
High operating temperature
Locate and correct cause of
overheating
Bind in steering column
Check column drag
Dirt or foreign matter
trapped in piston relief
Check piston relief
Bent or damaged king pins
and tie rods
Repair or replace king pins
and tie rods
Refer to servicing instructions
Front end load too great
Lighten load
Low oil level in steering
system
Fill oil reservoir as required
Air in system
Bleed system and check for
cause of air
Caster degree incorrect
Correct to Specifications
Wheel turns hard in one
direction
Metal or foreign material in
relief ball seat in piston of
steering gear
Remove and clean relief
valve seats or replace
damaged parts
No attempt to return to
straight ahead from
turns (may also be hard
steering complaint)
No positive caster
Set caster to 3o to 5o
positive caster
Hard Steering
Wheel turns hard in one or
both directions
16
Possible cause
Symptom
Darting, wandering
(oversteering)
Excessive backlash/freeplay
Possible cause
Remedy
Steering gear mounting
distorted
Shim mounting pads to
correct piston to bore
interference. Make sure
correct bolt length is used on
the base mount gears.
Linkage ball sockets seized
or binding
Check and repair or replace
King pins seized or binding
Repair or replace
Oil flow rate incorrect
Check and correct supply
pump
Oil flow too high
Supply pump not to
specifications
Air trapped in steering gear
Bleed system
Looseness, worn front end
parts
Check and repair as required
Front end alignment not
correct
Align front end caster
Overloading
Reduce loads
Rear axle not parallel
Check & repair as required
Tight tie rod ends & drag
link sockets
Check rotational torque &
replace if necessary
Worn universal joint
Replace universal joint
Pitman arm ball worn
“egg-shaped” (if equipped)
Replace pitman arm
assembly where riveted ball
is used.
Loose bracket frame to
bracket or bracket to gear
Remove bracket, clean
frame and bracket. Check
radius of frame making
sure bracket is not bearing
on radius surface.
Check bracket for wear
from being loose.
Replace bracket and tighten
to recommended torque
rating by size and grade of
bolts.
If necessary, replace
bracket.
Rack on piston damaged
Replace steering gear
Damaged sector
shaft/splines
Replace steering gear
Worn or damaged pitman
arm splines
Replace pitman arm and
sector shaft
Universal joint yoke loose
on actuating shaft
Repair or replace damaged
parts.
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Symptom
Steering input not smooth
Possible cause
Remedy
Worn universal joint
Check and replace as
required
Lack of lubrication
Lubricate per vehicle
manufacturer’s
recommendations
Universal joints not phased
properly
Re-phase columns*
Low oil flow
Idle speed too low
Drive belts slipping
Supply pump not to
specifications
Overload on front axle
Verify front axle weight.
Do not exceed rating of
front axle.
Pump cavitating
Correct pump supply
Overheating
Correct cause of overheating
NOTE:
Universal joints are designed to operate best when the angle between the drive and driven
shaft
is
a
maximum
of
20
to
25
degrees.
Angles greater than this may upset steering
performance.
IMPORTANT: Actuating shaft thread wear generally comes from improper lubrication or excessive manual
steering. Manual steering results from low pump pressure or flow or an overloaded
front axle.
*To check phasing of the universal joints in the steering column, use an inch-pound graduated dial type torque wrench.
With a socket on the steering wheel retaining nut, read the difference in the torque while steering from lock-to-lock.
Variation of more than 15 in.-lb. means improper phasing. Take the reading with the vehicle stationary and the engine
running at idle.
Phasing can usually be corrected by rotating the two-piece intermediate shaft one spline at a time until the torque
reading remains the same throughout the 360 degree rotation of the steering wheel.
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Common Procedures
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This section of the service manual covers repairs that do not require removal of the power steering gear. Before you attempt
repairs, read the procedure and make sure you have all the parts, tools and information needed to finish the job. Always refer
to the Vehicle Manufacturer’s Service Manual and any service bulletins covering the vehicle you are working on.
Read all the safety warnings. These warnings have information critical to the safe operation of the steering gear and
the vehicle.
Additionally, you will find notes, cautions and items marked “Important”. These items give information to ensure that you
are following proper procedures. They are designed to keep repair times to a minimum and assure a quality repair.
If problems arise during repair or you are unsure of a procedure, call the Field Service Department of the R. H. Sheppard
Co. at 717-633-4111 for assistance.
WARNING
REPAIRS TO HEAVY DUTY POWER STEERING SYSTEMS MUST BE MADE BY HIGHLY
TRAINED PROFESSIONAL MECHANICS.
FAILURE TO FOLLOW SAFETY PROCEDURES COULD RESULT IN LOSS OF STEERING,
ACCIDENT DAMAGE OR PERSONAL INJURY.
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Preventive Maintenance
Power steering fluid and filter change is necessary to keep the system clean. The use of high quality fluids and filters
will insure removal of contaminants and dissipate heat. The recommended interval for power steering fluid and filter
change is once a year.
TOOLS REQUIRED:
Drain pan
Shop towels
10” adjustable wrench
Hydraulic jack of a suitable size
Screwdriver
WARNING
FOR OTHER EQUIPMENT, TOOLS OR SAFETY PROCEDURES ALWAYS FOLLOW THE
VEHICLE MANUFACTURER’S PROCEDURES FOR LIFTING AND BLOCKING. CLEAN UP ALL
OIL SPILLS TO AVOID SLIPS AND FALLS.
PARTS REQUIRED:
Specified steering fluid
Specified filter
WARNING
NEVER USE OLD OR USED SEALS, COTTER PINS, RETAINERS OR CRITICAL FASTENERS.
ALWAYS BUY A NEW SEAL KIT. USE ONLY MANUFACTURER APPROVED REPLACEMENT
ADDITIONAL REFERENCES:
Vehicle Manufacturer’s Service Manual
R. H. Sheppard Co., Inc. Maintenance and Troubleshooting Video
PROCEDURE:
1. Park the vehicle on a clean, dry, solid surface. Set the parking brake, block the rear wheels and place the
transmission in neutral.
2. Raise the front end of the vehicle until the tires have cleared the surface using the hydraulic jack.
3. Tilt the hood or raise the cab using the procedure in the Vehicle Manufacturer’s Service Manual.
4. Place the drain pan under the steering gear to catch the fluid.
5. Remove the pressure and return lines from the steering gear to drain fluid.
6. Wipe off the area around the reservoir cap with a clean towel. Remove the bolt from canister type reservoirs.
Remove the cover.
7. Remove the filter from the canister and discard. If a spin on filter is used remove the filter using the filter
wrench and discard.
IMPORTANT: Discard only the filter element. The other parts may be used to retain the filter in the reservoir
assembly.
8. Wipe the inside of the reservoir canister clean with a clean shop towel.
9. With the hoses disconnected, slowly turn the steering wheel from full left to full right three or more times to
purge oil from the steering gear. Make sure the drain pan will catch the oil from the steering gear.
10. Attach the pressure and return lines to the steering gear and tighten.
11. Install a new filter element in the reservoir. Follow the directions on the filter element and refer to the Vehicle
Manufacturer’s Service Manual.
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12. Clean the reservoir cap with an approved solvent. Remove the old gasket from the cap and replace it with a new
gasket. For vehicles with a spin on filter element, replace the filter with using procedures in the Vehicle
Manufacturer’s Service Manual.
13. Fill the reservoir with new steering fluid to within 1” of the top of the reservoir canister. Install the reservoir
cover and tighten the bolt to the Vehicle Manufacturer’s specification.
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14. Start the vehicle and allow it to idle.
15. Check the fluid level and fill as needed.
16. Steer the vehicle from full left to full right several times and check the fluid level again. Add fluid as needed.
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17. Visually check all fittings and hoses for external leaks.
CAUTION
Do not allow the reservoir to empty during start up. Pump damage may result.
18. Shut the vehicle off. Remove the drain pan, lower the vehicle until the tires contact the surface and remove the
jack.
19. Lower the cab or hood using the procedures in the Vehicle Manufacturer’s Manual.
WARNING
DO NOT CHECK FOR LEAKS BY HAND, HYDRAULIC OIL UNDER PRESSURE CAN PENETRATE
THE SKIN AND CAUSE SEVERE INJURY.
NOTE: A note on mixing oils and additives-Chemicals tend to react with one another. Some interactions
are of no consequence. Others are beneficial, while still others may cause some degradation in the
service capability. It is not recommended to mix products which are intended for different service
applications, for instance, a transmission and a gear oil.
Since the original lubricant manufacturer puts a lot of time and expense into ensuring that their oil
will meet the required qualifications, it is not a good idea to introduce additional chemical which
may upset the delicate and critical balance originally obtained. This means that supplemental
additives are not needed and normally are not desired in a fully compounded and qualified lubricant.
21
Input Shaft Seal Replacement
(Current Production after July ‘1991)
IMPORTANT: Do not remove the steering gear for this repair.
TOOLS REQUIRED:
Appropriate size sockets and drivers to remove U-Joint pinch bolt and bearing cap mounting bolts
Drain pan
5/8” & 11/16” combination wrenches
0-150 ft./lb. torque wrench (minimum)
Screw driver
1” Socket & short extension (1/2” drive)
Small hammer
WARNING
FOR OTHER EQUIPMENT, TOOLS OR SAFETY PROCEDURES ALWAYS FOLLOW THE VEHICLE
MANUFACTURER’S PROCEDURES FOR LIFTING AND BLOCKING.
PARTS REQUIRED:
5542261 Input Shaft Seal Kit
Specified fluid
WARNING
NEVER USE OLD OR USED SEALS, COTTER PINS, RETAINERS OR CRITICAL FASTENERS. ALWAYS
BUY A NEW SEAL KIT. USE ONLY MANUFACTURER APPROVED REPLACEMENT PARTS.
ADDITIONAL REFERENCES:
Vehicle Manufacturer’s Service Manual
R. H. Sheppard Co. Maintenance & Troubleshooting Video (Optional)
PROCEDURE - Disassembly:
NOTE : Removal of the power steering gear is not necessary to complete this repair.
1.
2.
3.
4.
Park the vehicle on a clean, dry, solid surface, preferably concrete. Set the parking brake and block the wheels.
Place the transmission in neutral.
Tilt the hood or cab using the procedure in the Vehicle Manufacturer’s Service Manual.
Loosen and remove the pinch bolt on the lower end yoke of the steering shaft.
Remove the lower yoke from the steering gear input shaft. If necessary, secure the shaft so it will not be
in the way.
IMPORTANT : Do not pull the slip shaft out of the steering shaft. This would require rephasing at time of
installation.
5.
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Place the drain pan under the power steering gear. Draining the system is not necessary, but some fluid
will be lost.
CAUTION
6.
Make sure the cap you are working on
has a rubber lip seal before attempting
repair.
Remove the rubber dust boot. Using the ratchet and socket,
remove the four attaching bolts from the bearing cap cover and
remove the bearing cap cover.
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DO NOT TURN THE INPUT SHAFT
DURING REPAIRS. DAMAGE TO THE
STEERING GEAR WILL RESULT.
WARNING
CAUTION
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The thrust washer will stick to the
bearing cap cover. Install the thrust
washer into the bearing cap before
proceeding.
7.
Place the bearing cap cover on a clean work surface. Pry the
salt seal out of the bearing cap cover.
8.
Press the oil seal out of the cover using a suitable size socket or
seal driver. Use of an arbor press is recommended. Some steering gears will have a protective washer behind the oil seal.
Press all components out of the cover. Remove the o-ring from
the cover. Discard all seals. Retain the washer for use when
new seals are installed.
9.
Clean the cover with a suitable solvent. If the cap you are
working on has a grease fitting, remove the grease fitting
and fill the hole with RTV compound. No further greasing is
required.
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Reassembly
1.
Place the cover face down on a clean work surface. Coat the
outside diameter of the seal with clean chassis lube. Install the
oil seal in the cover using a suitable size seal driver and an
arbor press. Make sure the lip of the seal faces up when
installing the seal.
NOTE: The seal with a gold garter spring is the oil seal. This seal
is directly interchangeable with all prior seals.
2.
Install the protective washer (if equipped) into the bearing cap
cover using an arbor press and suitable size seal driver. Install
a new o-ring on the bearing cap cover.
3.
Press the salt seal into the cover until it is flush with the face of
the cover. There is a choice of two salt seals for the M-series
gear. Select the proper salt seal for your cover and press it into
the cover until it is flush with face of the cover.
NOTE: Tape the input shaft splines before installing the cover to
prevent seal damage.
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4.
Install the bearing cap cover onto the steering gear and torque
the attaching bolts to specification. Install the rubber boot over
the input shaft. Insure the boot is below the spine and contacts
the cover when installed.
5.
Remove the tape from the splines and install the u-joint
following the vehicle manufacturer’s instructions.
6.
Check and correct the fluid level in the power steering
reservoir.
7.
Start the vehicle and check for leaks. Remove the drain pan
and lower the hood or cab following vehicle manufacturer’s
guidelines.
Sector Shaft Seal Replacement
Do Not Remove the Steering Gear for This procedure
Partial disassembly of the steering gear is required to replace
the sector shaft seals. Take care to time the sector shaft if it is
replaced.
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Tools Required:
Drain Pan
Hammer
Punch
Appropriate Size Allen Drive socket
Sheppard Pitman Arm Puller (Kent Moore #ZTSE-4439)
Sockets& ratchet
Large Snap Ring Pliers
Seal Driver
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Procedure:
1.
Park the vehicle on a clean dry surface. Set the
parking brake and chock the wheels. Tilt the hood or
cab to gain access to the steering gear.
2.
Remove the pitman arm following the procedures
in the Pitman Arm Removal Section of this manual.
3.
Remove the rubber boot from the sector shaft and
discard. Snap Ring covers may be equipped with a
protective cap. Pry the cap out of the bore at this
time.
4.
There are three variations of sector shaft covers. Use
appropriate procedures for removal of the cover you
are working with. You will need either the snap ring
pliers, socket and ratchet or Allen drive sockets to
remove the particular attachment method you are
working with.
IMPORTANT: You will need to remove the factory
installed silicone protectant from the snap ring and
carefully clean the cover area before disassembly when
working with snap ring covers.
25
5.
Clean the shaft and remove the sector shaft cover. It
may be necessary to crank the engine to force the
cover out of the housing
NOT TURN THE WHEEL
WARNING DO
DURING THIS PROCEDURE!
CIRCULATING OIL WILL FORCE THE COVER OUT.
TURNING THE WHEEL WILL CAUSE A PRESSURE
INCREASE AND PERSONAL INJURY MAY RESULT!
NOTE: A slide hammer may be used to remove the
sector shaft if necessary.
6.
Remove the sector shaft and cover from the housing.
Separate the cover from the sector shaft. Inspect the
sector shaft for corrosion or damage. Replace the
sector shaft if necessary.
NOTE: It may be necessary to remove the dust cover
from the frame side of the sector shaft. Use a gasket
scraper or screwdriver to remove the frame side dust
cover.
7.
Pry the excluder seal from the cover. Using a seal
pick, remove the oil seal from the sector shaft cover
and housing. Remove the O-ring from the cover.
Discard all seals.
8.
Install a new oil seal in the housing and cover. Take
care to install the oil seal with the black lip toward
the inside of the gear and the blue side facing the
outside of the gear
SECTOR SHAFT OIL SEALS
WARNING THE
ARE TWO PIECE SEALS IT WILL
BE NECESSARY TO BEND THE SEAL TO INSTALL IT
INTO THE COVER AND HOUSING. ONCE THE
SEAL IS IN PLACE, IT MAY BE NECESSARY TO
SEAT THE SEAL INTO PLACE USING YOUR
FINGERS OR A BLUNT SEAL PICK. TAKE CARE TO
PUSH ONLY ON THE BODY OF THE SEAL AND
NOT ON THE SEAL LIP!
NOTE: Coat all seals with a light coat of clean motor
oil to facilitate installation of the sector shaft.
26
9.
Install the sector shaft into the housing taking care
to align the timing mark on the sector with the
timing marks on the piston. It may be necessary to
tap on the sector shaft to properly seat it into the
housing.
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10. Install the sector shaft cover onto the steering gear.
Insure that the cover is properly seated when
installing. Snap ring covers must be flush or below
the snap ring groove when properly installed.
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11. Install the snap ring or attaching bolts in the cover.
TO PROPERLY INSTALL
WARNING FAILURE
THE SNAP RING CAN CAUSE
THE SNAP RING TO DISENGAGE AND PERSONAL
INJURY WILL RESULT!
12. Using an appropriate size seal driver, install the
excluder seal in the cover. Apply a coat of clean
chassis lube in the lip of the seal before installing.
Apply a bead of grease over the excluder seal and
slide the rubber boot over the sector shaft.
13. Install the pitman arm following the procedures in
the Pitman Arm Installation section of this manual.
14. Fill the system with an approved fluid. Start the
engine, check and correct fluid level.
15. Lower the hood or cab following the vehicle
manufacturers guidelines
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Bleeding Single Gear System
Bleeding of the steering gear in a single gear system is only necessary if the gear is mounted in a way that will trap
air in the sector shaft bore. This procedure should he followed whenever the gear has been disassembled or replaced.
TOOLS REQUIRED:
1/8” Allen wrench
WARNING
FOR OTHER EQUIPMENT, TOOLS OR SAFETY PROCEDURES ALWAYS
FOLLOW THE VEHICLE MANUFACTURER’S PROCEDURES FOR
LIFTING AND BLOCKING.
ADDITIONAL REFERENCES:
Vehicle Manufacturer’s Service Manual
R. H. Sheppard Co. - Maintenance & Troubleshooting Video (Optional)
PROCEDURE:
1. Park the vehicle on a clean, dry, solid surface-preferably concrete. Set the parking brake and block the wheels.
Place the transmission in neutral.
2.
Tilt the hood or cab using the procedure in the Vehicle Manufacturer’s Service Manual.
3.
Make sure the fluid level in the reservoir is at the full mark of the dipstick.
4.
If this is a replacement steering gear, follow the “Plunger Adjustment Procedures” in this section of the
manual.
5.
Start the vehicle and allow the engine to idle.
6.
Steer the vehicle from full left to full right several times. The pitman arm must make full travel.
7. Locate the bleeder screw in the plug located on
the sector shaft bore (Figure 34).
IMPORTANT:
Do not turn the steering wheel with the bleeder open.
8.
Using the allen wrench, open the bleeder screw until non-aerated fluid flows from the bleed screw.
9.
Tighten the bleed screw.
10. Repeat steps 5-8 until no aeration is found in the bleed oil.
11. If this is a replacement steering gear, follow the “Plunger Adjustment Procedures” in this section of the
manual.
12. Check the fluid level in the power steering reservoir and fill if necessary.
13. Shut the vehicle off.
14. Lower the hood or cab following procedures in the Vehicle Manufacturer’s Service Manual.
15. Remove wheel blocks
28
Bleeding Dual Gear System
Bleeding the dual steering gear system is necessary whenever the system has been repaired. Different gear sizes may
be used together but the bleeding procedure is the same.
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TOOLS REQUIRED:
Hammer
1/8” Allen wrench
Ball stud removal tool
Hydraulic jack - appropriate size
0-200 ft./lb. Torque wrench (l/2” drive)
Socket and ratchet for drag link nut (l/2” drive)
WARNING
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FOR OTHER EQUIPMENT, TOOLS OR SAFETY PROCEDURES ALWAYS
FOLLOW THE VEHICLE MANUFACTURER’S PROCEDURES FOR LIFTING
AND BLOCKING.
PARTS REQUIRED:
Cotter pins
Specified fluid
WARNING
NEVER USE OLD OR USED SEALS, COTTER PINS, RETAINERS OR CRITICAL
FASTENERS. ALWAYS BUY A NEW SEAL KIT. USE ONLY MANUFACTURER
APPROVED REPLACEMENT PARTS.
ADDITIONAL REFERENCES:
Vehicle Manufacturer’s Service Manual
R. H. Sheppard Co. - Maintenance & Troubleshooting Video (Optional)
PROCEDURE:
1.
2.
Park the vehicle on a clean, dry, solid surface-preferably concrete. Set the parking brake and block the wheels.
Place the transmission in neutral.
Jack the vehicle up until the front wheels have cleared the surface.
3.
4.
Tilt the hood or cab using the procedure in the Vehicle Manufacturer’s Service Manual.
Make sure the fluid level in the reservoir is at the full mark on the dipstick.
IMPORTANT: Do not allow the reservoir to empty during this procedure. pump damage or further aeration
can result.
5.
6.
7.
Remove the drag links from the pitman arms of the master and slave gears using the procedure in the Vehicle
Manufacturer’s Service Manual.
Start the vehicle and allow the engine to idle.
Turn the steering wheel to a full left turn and hold until the slave gear moves its full travel. Then turn
the steering wheel to a full right turn and hold until the slave moves its full travel. Repeat this procedure
three or more times.
29
8.
Connect the drag link to the master gear. Torque the attaching nut following the procedures in the Vehicle
Manufacturer’s Service Manual
CAUTION
9.
Do not back off the nut when locating the cotter pin hole.
Install a new cotter pin through the ball stud nut, then lock in place.
DANGER
FAILURE TO INSTALL A NEW COTTER PIN IN THE BALL STUD AFTER
PROPER TORQUE COULD RESULT IN LOSS OF STEERING CONTROL.
10. With the master gear drag link connected, turn the steering wheel to a full left turn and hold until the slave gear
pitman arm moves its full travel. Then turn the steering wheel to a full right turn and hold until the slave gear
pitman arm moves its full travel. Repeat this procedure three or more times.
11. Connect the drag link to the slave gear by turning the steering wheel until the pitman arm lines up with the drag
link.
IMPORTANT:
Do not move the pitman arm by hand during this operation. Air may get in the system.
12. Torque the attaching nut following the procedures in the Vehicle Manufacturer’s Service Manual.
13. Install a new cotter pin through the ball stud nut, then lock in place.
14. Steer the vehicle full left to full right several more times.
15. Locate the bleeder screw in the master gear located in the plug on the sector shaft bore
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16. Using the allen wrench open the bleeder screw until non-aerated fluid flows from the bleed screw.
NOTE: Do not turn the steering wheel with the bleeder open.
17. Repeat the procedure on the slave gear if an M-Series slave is used.
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18. Check and correct fluid level.
19. Shut the vehicle off.
20. Lower the the hood or cab following the procedure in the Vehicle Manufacturer’s Service Manual.
21. Lower the vehicle until the tires contact the surface and remove the jack.
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Axle Stop Adjustment
Axle stop adjustment should be checked during pre-delivery. Axle stop positioning will determine the maximum
wheel cut available for your truck and can be adjusted using the adjustable bolt and lock nut on each spindle. The
following procedure is a guide. Refer to the OEM specifications for specific wheel cuts for your vehicle.
TOOLS REQUIRED:
Hydraulic Jack
Wrenches to fit Stop Bolts
PROCEDURE:
1.
Park the vehicle on a solid surface. Set the parking brake, chock the wheels and tilt the hood or cab to access
the front tires.
2.
Raise the front of the vehicle until the tires clear the surface.
3.
Turn the wheels to a full right turn. Note the position of the tire relative to the steering gear or drag link. Adjust
the stop bolt on the right spindle until a minimum clearance of 1” is maintained between the tire and any part of
the chassis. This is the maximum wheel cut available.
WARNING
4.
Turn the wheels to a full left turn. Note the position of the tire relative to contact with any part of the chassis or
component. Adjust the stop bolt on the left spindle until a minimum clearance of 1” is maintained between the
tire and any part of the chassis or component. This is the maximum wheel cut available.
WARNING
5.
32
DO NOT EXCEED THE MINIMUM CLEARANCE OF 1”, NEVER ALLOW THE TIRE TO
CONTACT ANY PART OF THE CHASSIS. CONTACT OF THE TIRE WITH ANY PART OF
THE CHASSIS WILL RESULT IN TIRE OR STEERING COMPONENT DAMAGE.
DO NOT EXCEED THE MINIMUM CLEARANCE OF 1”, NEVER ALLOW THE TIRE TO
CONTACT ANY PART OF THE CHASSIS. CONTACT OF THE TIRE WITH ANY PART OF
THE CHASSIS WILL RESULT IN TIRE OR STEERING COMPONENT DAMAGE.
Make sure the jam nuts are tight on both axle stop bolts. Lower the vehicle, lower the hood or cab and remove
the chocks.
Alternate Bleed Procedure
Single Gear System
In most cases, trapped air will bleed from the steering system by following the “Single Gear Bleeding Procedure.” Air
entrapment is most typical in applications where the sector shaft bore is above the piston bore on the steering gear as
shown below. If you are unable to remove all the air following this procedure it may be necessary to bleed the system
as follows:
1.
With the full weight of the vehicle on the steer tires, start the truck and turn the wheels to a full left turn.
2.
With the wheels turned full left, locate the bleeder screw above the pitman arm.
3.
Using a 1/8” Allen wrench, open the bleed screw 2-3 turns.
4.
With the bleed screw open, turn the wheels to a full right turn.
5.
Close the bleed screw when a full right turn is achieved.
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IMPORTANT:
Turning the wheels to a full right turn with the bleed screw open will force air from the system under pressure.
DO NOT steer the truck to the left with the bleed screw open as this will introduce additional air into the system.
6.
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Repeat this procedure 2-3 times until all air is removed from the system.
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Manual Plunger Adjustment
Relief plunger adjustment should be checked during pre-delivery. Any time tire size or steering gears are changed,
relief plunger adjustment will be necessary. A relief plunger is located in each end cap of the steering gear; One for
right turn, one for left turn.
TOOLS REQUIRED:
Small blade screwdriver
WARNING
FOR OTHER EQUIPMENT, TOOLS OR SAFETY PROCEDURES ALWAYS FOLLOW
THE VEHICLE MANUFACTURER’S PROCEDURES FOR LIFTING AND
BLOCKING.
ADDITIONAL REFERENCES:
Vehicle Manufacturer’s Service Manual
R. H. Sheppard Co. - Maintenance & Troubleshooting Video (Optional)
PROCEDURE:
NOTE: Never attempt to adjust relief plungers until the axle stops are set following Vehicle Manufacturer’s
Specifications.
1.
Park the vehicle on a clean, dry, solid surface-preferably concrete. Set the parking brake and block the wheels.
2.
Place the transmission in neutral and start the engine.
3.
Allow the engine to operate at idle speed.
NOTE: It is always best to have 2 people when setting plungers; 1 to steer the vehicle and 1 to set and check
adjustments.
4.
Locate the plungers.
5.
Determine which plunger is used to adjust right and left turns based on direction of pitman arm travel.
6.
Turn the steering wheel to a full left turn and check the clearance If the clearance is not 1/8”, plunger adjustment
will be necessary
WARNING
7.
IF THE STOP BOLT HITS THE AXLE UNDER PRESSURE, RELEASE THE WHEEL
IMMEDIATELY! DAMAGE TO STEERING COMPONENTS MAY RESULT.
Return the front tires to the straight ahead position and release the steering wheel. Using the screwdriver, adjust
the plunger for left turn Turning the plunger in will increase the clearance between the stop bolt and the axle,
while turning the plunger out will decrease the clearance. Do not adjust the plunger with pressure on the
steering wheel Seal damage can result.
WARNING
NEVER ADJUST THE PLUNGER BEYOND FLUSH WITH THE END CAP.
LEAKAGE OR PERSONAL INJURY MAY RESULT.
8.
Turn the steering wheel to a full left turn. Check the 1/8” clearance.
9.
If further adjustment is required, repeat steps 7 & 8 until the l/8” clearance is achieved.
10. Repeat steps 6 thru 9 for the right turn.
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Set Automatic Plungers
Automatic plungers are set at the factory and do not need to be set unless tire size is changed or wheel cut is
extended. It is recommended that the setting of automatic plungers be checked at pre-delivery. Do not adjust or set
Auto Plungers unless axle gap is wrong or tire size is changed! All Sheppard Auto Plunger equipped steering gears
are manufactured with the auto plungers set for minimum wheel cut. Once set following this procedure, no other
adjustment or setting is required
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TOOLS REQUIRED:
Hydraulic Jack
PROCEDURE:
1.
Park the vehicle on a solid surface. Set the parking brake,
chock the wheels and tilt the hood or cab to access the
front tires.
2.
Verify that your steering gear has auto plungers.
Steering gears with auto plungers will have the word
“AUTO” cast into the housing as shown. Plastic caps
on the plunger hole is a secondary means of verification
3.
Raise the front wheels until the tires clear the surface.
Make sure axle stops are set to manufacturers specifications.
4.
Start the engine and turn the wheel to a full lock in both
directions. Contacting the axle stop with the wheels off
the ground will set the auto plunger to the correct position.
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NOTE: As you reach the end of travel, you will feel
the piston contact the plunger. Continue turning
until you reach the axle stop bolt.
5.
Return the wheels to straight ahead. Lower the vehicle.
6.
Shut off the engine. Lower the hood or cab and remove
the wheel chocks.
35
Adjust Automatic Plungers
Auto Plungers require NO ADJUSTMENT unless tire size is changed or wheel cut is reduced. Do not adjust auto
plungers unless you are in one of these conditions!
TOOLS REQUIRED:
1/4” Punch
Ball Peen Hammer
DO NOT USE A SCREWDRIVER TO ADJUST AUTO PLUNGERS!
PROCEDURE:
1.
Park the vehicle on a solid surface. Set the parking
brake, chock the wheels and tilt the hood or cab to
access the front tires.
2.
Verify that your steering gear has auto plungers.
Steering gears with auto plungers will have the
word “AUTO” cast into the housing as shown.
Plastic caps on the plunger hole is a secondary
means of verification.
3.
Remove the plastic caps from both plunger holes.
Carefully insert the 1/4” plunger into the plunger
hole and drive the auto plunger in until it bottoms in
the bore. Repeat this procedure for both ends of the
steering gear. Replace the plastic caps.
TAKE CARE WHEN USING THE PUNCH
TO INSURE PLUNGER BORE IS NOT
DAMAGED. A LEAK CAN OCCUR IF THE BORE IS
DAMAGED DURING THIS PROCEDURE.
WARNING
IMPORTANT: Make sure there are no sharp edges on
your punch that could damage the bore.
4.
36
Set the Auto Plunger following the “Set Automatic
Relief Plungers” section of this manual.
Auto Plunger Repair Procedure
Under normal use the Sheppard Auto Plunger system requires no regular maintenance. The auto plunger is
serviceable only as a kit and is only required if a leak is present.. Sheppard part number 18212821K will fit
both the cylinder head and bearing cap end of the steering gear.
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TOOLS REQUIRED
Various Metric Sockets and Ratchet
Slotted Screwdriver Bit arid Suitable Socket and Ratchet
l/4” Drift Punch
1/4” Pin Punch
1/4” Center Punch
10mm open End Wrench
Hammer
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CYLINDER HEAD REPAIR PROCEDURE
1.
Park the vehicle on a clean dry surface (preferably
concrete). Set the parking brake and block the wheels. Tilt
the hood or raise the cab following the procedures outlined
in the vehicle manufacturer’s service manual. Identify the
steering gear as being equipped with auto plungers. If you
have a question on identifying the steering gear, contact the
Field Service Department of the R. H. Sheppard Co. Place
a drain pan under the steering gear.
2
Mark the cylinder head and housing for re-assembly.
Remove the four attaching bolts from the cylinder head
using an appropriate size socket and ratchet.
Remove the cylinder head
3.
Place the cylinder head in a vise. Remove the plastic plug
from the auto plunger hole. Using a 1/4” punch and
hammer, drive the auto plunger assembly in until it
bottoms in the bore. The spring pin, flange and plunger
body should be accessible for repair at this point ho
Failure to keep the 1/4” punch straight
in the bore or hitting the plunger too
hard can result In damage to the steering gear or
auto plunger assembly.
CAUTION
4.
Carefully insert the screwdriver bit into the plunger bore to
engage the slotted head of the plunger body. Using the
10mm open end wrench to hold the flange across the flat
sides, carefully turn the flange to remove the flange from
the plunger body. Do not allow the screwdriver bit to slip
off the plunger body in the process, damage to the bore
can result. Discard the flange.
NOTE: The auto plunger flange is held in place with patch
lock and the threads are staked at the factory It will require
approximately 15-20 inch pounds of torque to remove the
flange.
5.
Remove the plunger body from the spring pin and discard.
It may be necessary to tap the plunger body to remove it
from the spring pin. Use of a 1/8” pin punch is
recommended.
37
6.
Coat the O-ring of the plunger assembly with a light coat
of grease and install the plunger body through the spring pin.
IMPORTANT: Check the plunger bore for nicks or gouges
before installing the plunger assembly. Take care not to
introduce dirt or contaminants in the plunger bore when
reassembling.
7.
Use the screwdriver bit and ratchet to hold the plunger
body. Screw the flange onto the plunger body using the
10mm open end wrench until the flange contacts the spring
pin.
NOTE: The plunger body has patch lock on the threads and
will require approximately 15 to 20 inch pounds of torque
to overcome the patch lock.
WARNING
8.
THE FLANGE MUST CONTACT THE
SPRING PIN. STEERING GEAR
DAMAGE OR A LEAK CAN RESULT.
With the flange against the spring pin, use the center punch
to stake the threads of the plunger body. Take care to not
bend the plunger when staking the threads.
USE EXTREME CAUTION WHEN
STAKING THE THREADS OF THE
PLUNGER BODY. HITTING THE THREADS TOO HARD
WILL BEND THE PLUNGER AND CAUSE STEERING
FAILURE
WARNING
9.
Install the cylinder head onto the steering gear taking care
to align the marks from disassembly. Torque the
attaching bolts to specification. Install the plastic cap over
the plunger boss.
10. Fill the reservoir with an approved fluid. Start the engine.
Check and correct the fluid level and check for leaks.
11. Set the auto plungers following the procedure in this
manual. Lower the hood or cab following the procedures in
the vehicle manufacturer’s service manual.
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Bearing Cap of Input End Auto Repair
1.
Park the vehicle on a clean dry surface (preferably concrete). Set the parking brake and block the wheels. Tilt
the hood or raise the cab following the procedures outlined in the vehicle manufacturer’s service manual.
Identify the steering gear as being equipped with auto plungers. if you have a question on identifying the
steering gear, contact the Field Service Department of the R. H. Sheppard Co. at 1-800-274-7437. Place a drain
pan under the steering gear.
2.
Mark the bearing cap and housing for re-assembly. Remove the universal joint from the input shaft of the
steering gear.
3.
Remove the plastic plug from the plunger hole and drive
the auto plunger in until it bottoms using the l/4” punch
and hammer. Remove the four attaching bolts from the
bearing cap using an appropriate size socket and ratchet.
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Failure to keep the 1/4”punch straight
in the bore or hitting the plunger too
hard can result in damage to the steering gear or
auto plunger assembly.
CAUTION
4.
Separate the bearing cap assembly from the housing by
turning the input shaft out of the housing. Turn the shaft
until it stops.
DO NOT FORCE THE SHAFT WHEN
TURNING IT OUT OF THE HOUSING.
BINDING OF THE SHAFT AND STEERING GEAR
DAMAGE CAN RESULT.
DANGER
5.
Carefully insert the screwdriver bit into the plunger bore to
engage the slotted head of the plunger body. Using the
10mm open end wrench to hold the flange across the flat
sides, carefully turn the flange to remove the flange from
the plunger body. Do not allow the screwdriver bit to slip
off the plunger body in the process as damage to the bore
can result. Discard the flange.
NOTE: The auto plunger flange is held in place with patch
lock and the threads are staked at the factory. It will require
approximately 15-20 inch pounds of torque to remove the
flange
6.
Remove the plunger body from the spring pin and discard.
It may be necessary to tap the plunger body to remove it
from the spring pin. Use of a 1/8” pin punch is
recommended.
7.
Coat the O-ring of the plunger assembly with a light coat of
grease and install the plunger body through the spring pin.
IMPORTANT: Check the plunger bore for nicks or gouges
before installing the plunger assembly. Take care not to
introduce dirt or contaminants in the plunger bore when
reassembling.
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8.
Use the screwdriver bit and ratchet to hold the plunger body. Screw the flange onto the plunger body using the
10mm open end wrench until the flange contacts the spring pin.
NOTE: The plunger body has patch lock on the threads and will require approximately 15-20 inch pounds of torque
to overcome the patch lock
WARNING
9.
THE FLANGE MUST CONTACT THE SPRING PIN. STEERING GEAR DAMAGE OR A
LEAK CAN RESULT
With the flange against the spring pin, use the center punch to stake the threads of the plunger body Take care to
not bend the plunger when staking the threads.
DANGER
USE EXTREME CAUTION WHEN STAKING THE THREADS OF THE PLUNGER BODY.
HITTING THE THREADS TOO HARD WILL BEND ThE PLUNGER AND CAUSE STEERING
FAILURE
10. Remove the block and install the bearing cap assembly onto the housing taking care to align the reassembly
marks made earlier. Install the plug in the plunger hole. Torque the attaching bolts to specifications.
11. Install the universal joint onto the steering gear input shaft following the procedures in the vehicle
manufacturer’s service manual.
12. Fill the reservoir with an approved fluid. Start the engine, check and correct the fluid level and check for leaks
13. Set the auto plungers following the procedure in this manual. Lower the hood or cab following the procedures in
the vehicle manufacturer’s service manual.
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Pitman Arm Removal
It may be necessary to remove the pitman arm on some vehicles before removing the steering gear. Proper technique
in removing the pitman arm will avoid damage to the steering gear, pitman arm and retainer.
TOOLS REQUIRED:
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Hammer
Tapered Punch
Appropriate Size Allen Drive Socket - 5/8” or 3/4”
Sheppard Pitman Arm Puller - Kent Moore part number ZTSE4439 or
Three Jaw Puller
Impact Wrench
WARNING
FOR OTHER EQUIPMENT, TOOLS OR SAFETY PROCEDURES ALWAYS FOLLOW THE
VEHICLE MANUFACTURER’S PROCEDURES FOR LIFTING AND BLOCKING
WARNING
THE PITMAN ARM WILL BE EXTREMELY TIGHT. DO NOT USE A HAMMER OR APPLY
HEAT TO THE ARM. DAMAGE TO THE SECTOR SHAFT, PITMAN ARM OR SEALS
CAN RESULT.
1.
Park the vehicle, set the parking brake and raise the hood
or cab.
2.
Use the punch to bend the restraining tabs out of the
pitman arm retainer.
IMPORTANT: Do Not bend the aligning tabs out of the
pitman arm.
3.
Lubricate the face of the retainer with clean chassis
lube.
IMPORTANT: Failure to lubricate the face of the retainer
will cause difficulty in removing the pitman arm.
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4.
Slide the pitman arm puller over the pitman arm as shown.
Take care to align the hole in the puller with the Allen
socket in the retainer. Insert the Allen drive socket through
the puller and into the retainer socket. Use an impact
wrench to back off the retainer. The retainer will act as a
jack screw to remove the pitman arm.
NOTE: It will be necessary to remove the sector shaft cover
bolts to slide the puller over the arm if the gear you are
working on has a bolt on cover.
THE PITMAN ARM WILL BE EXTREMELY
TIGHT DO NOT POUND ON THE ARM
OR APPLY ANY SOURCE OF HEAT TO THE ARM!
DAMAGE TO THE PITMAN ARM OR SECTOR SHAFT
CAN CAUSE AN ACCIDENT AT A LATER DATE. NEVER
WELD THE PITMAN ARM OR SECTOR SHAFT!
DANGER
42
Pitman Arm Installation
Proper pitman arm installation is critical to the safe operation of the vehicle. Correct torque values are very
important! Always follow these procedures when installing the pitman arm.
DANGER
IF THE PITMAN ARM IS NOT APPLIED TO THE PROPER SPECIFICATIONS IT CAN COME
LOOSE AND CAUSE AND ACCIDENT. ANYTIME A PITMAN ARM IS FOUND LOOSE
REPLACE THE PITMAN ARM AND THE SECTOR SHAFT.
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TOOLS REQUIRED:
Appropriate Size Allen Drive Bit
Torque Wrench
Hammer
Punch
Anti-Seize Compound
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NOTE: Mount the steering gear on the frame to make pitman arm installation easier
Procedure:
1.
Install the pitman arm onto the sector shaft taking care
to align the timing marks.
2.
Install the pitman arm retainer into the sector shaft.
Take care to align the tabs in the notches of the arm.
Coat the threads of the retainer with Anti-Seize
compound. A Coating of Anti-Seize should be applied
to both sides of the friction washer if a new retainer
is being used.
IMPORTANT: Take note of the torque value on the face
of the retainer. Always torque the retainer to the
specified value.
M100 - 350 Foot Founds
M110 - 550 Foot Pounds
M80 - 225 Foot Pounds
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3.
Torque the retainer to the specified value using the
appropriate size Allen drive bit.
4.
Continue torquing the retainer past the specified value
until two of the notches in the retainer align with the tabs
of the washer.
DANGER
DANGER DO NOT BACK OFF THE
TORQUE VALUE TO ALIGN THE TABS!
A LOOSE PITMAN ARM OR LOSS OF STEERING
CONTROL COULD RESULT.
5.
Use the punch and hammer to bend the restraining tabs
of the washer into the notches of the retainer. Apply
torque putty to the tabs for future reference.
ONCE THE RETAINER IS TORQUED TO
SPECIFICATIONS AND LOCKED IN
PLACE, DO NOT RE-TORQUE THE RETAINER.
CONSTANT TORQUING OF THE RETAINER CAN
CAUSE A LOOSE PITMAN ARM OR LOSS OF
STEERING CONTROL.
DANGER
44
M110P2 Input Shaft Seal Replacement
Remove the steering gear and disassemble per the instructions for disassembly in this manual.
TOOLS REQUIRED:
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Assorted Sockets
Sharp Chisel
Hammer
Small Bladed Screwdriver
Bench Vise
PROCEDURE:
1.
Clamp the bearing cap and shaft assembly in the vise
with the ball thread facing up.. Remove the relief
plunger using the screwdriver.
2.
Use the chisel and hammer to split the star nut at the
grooves of the adjusting nut. Remove and discard the
star nut.
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NOTE: Use care when splitting the star nut to avoid
damaging the adjusting nut.
3.
Using a spanner wrench remove the shaft retaining nut
from the bearing cap.
4.
Carefully remove the valve shaft from the bearing cap.
Do not turn the shaft during removal as seal damage
could result.
IMPORTANT: Do not remove the rotary valve seals!
5.
Remove the inner thrust assembly from the valve shaft.
Note the order of the thrust assembly for reassembly.
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6.
Remove the outer thrust assembly from the bearing cap
bore. Note the order of assembly for reassembly.
IMPORTANT: Do not remove the rotary valve seals!
7.
Place the bearing cap on a clean work surface. Remove
the outer salt seal.
8.
Using an appropriate size seal driver, push the oil seal
out of the bearing cap.
9.
Using an appropriate size seal driver, install the oil seal
from the inside. Use of an arbor press is recommended.
A light coat of lubrication should be applied to the out
side diameter of the oil seal. The lip of the seal should
face the inside of the bearing cap. The garter spring of
the seal will be visible when properly installed.
10. Press the salt seal into the bearing cap until it is flush
with the face of the cap. Coat both seals with clean
grease before installing the rotary valve shaft.
46
11. Tape the input shaft splines to prevent seal damage.
Place the outer thrust assembly on the rotary valve. The
thrust bearing will go toward the valve, the thrust
washer will ride on the bearing cap surface.
NOTE: Apply a light coat of clean grease to the thrust
assembly to hold it in place during assembly.
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12. Carefully install the rotary valve shaft into the bearing
cap. Do not damage the input shaft oil seal when
installing the valve assembly. Do not turn the shaft
during installation. Remove the tape from the splines.
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13. Install the inner thrust assembly onto the rotary valve
shaft. The thrust bearing will ride on the face of the
valve and the thrust washer will ride against the shaft
retaining nut.
14. Install the shaft retaining nut until it contacts the thrust
assembly. Tighten the shaft retaining nut to pre-load the
thrust assembly. When properly set, the shaft will turn
freely without end play.
NOTE: Valve pre-load can be measured by turning the input
shaft with an inch pound torque wrench. When properly set
the radial drag will not exceed 25 inch pounds.
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15. Install the locking nut over the shaft retaining nut. Using
a spanner wrench tighten the locking nut until two tangs
align with the oil flow holes of the bearing cap. Bend the
locking tabs into the holes to secure the locking nut.
CAUTION
Do not bend the locking tabs into
the threaded plunger hole in the
bearing cap.
16. Stake the flange of the locking nut into the slots of the
shaft retaining nut. Take care when staking to not break
the flange.
17. Install a new O-ring and tetra-seal in the bearing cap.
Coat both seals with clean grease for installation. Install
the boot over the input shaft splines.
18. Install the plunger into the bearing cap. Reassemble
the steering gear following the procedures in the
re-assembly portion of this manual.
IMPORTANT: If your steering gear was originally built
with a grease fitting in the bearing cap, remove the fitting
and fill the hole with RTV to prevent ingestion of
contaminants. No further lubrication is required.
48
Disassembly
Complete disassembly of the steering gear is not recommended as a normal repair practice. The Sheppard M-Series
gears are designed to be serviced without removing the steering gear from the chassis. Before removing the
steering gear from the chassis, you must verify that hydraulic supply performance and system operation are within
specification.
IMPORTANT: The Sheppard M-Series steering gear is a precision machined component. Care must be taken to keep
it free form dirt and foreign material. All internal parts should be handled carefully to avoid damage to machined
surfaces. Repairs should not be completed on a hard surface bench to avoid nicks or burrs which can cause damage to
mating parts. Remove all nicks and burrs with a fine grit hand stone before assembling.
1.
Remove the pitman arm following the instructions in
the Pitman Arm Removal section found in the Common
Procedures portion of this manual
2.
Remove all external seals from the steering gear,
including the sector shaft dust boot, snap ring protective
cover (if equipped), frame side protective disk and the
input shaft dust boot.
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Discard all outer protective seals.
3.
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Mark the end caps for reassembly.
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4.
Remove the sector shaft cover using the appropriate
tools for the steering gear you are working on. There are
three methods of attachment for the sector shaft cover.
Snap ring design, bolt on or clip style as shown.
Bolt On Cover
Clip Style Cover
50
5.
Using a soft hammer, remove the sector shaft and cover
by tapping on the end of the sector shaft. The sector
shaft and cover will come out together.
6.
Carefully separate the sector shaft and cover.
7.
Remove the sector shaft oil seal from the cover using a
blunt seal pick. Discard the oil seal. Remove and
discard the cover O-ring.
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8.
Remove the excluder seal from the sector shaft cover
using a screwdriver.
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NOTE: Take care when removing the excluder seal. Do
not damage the seal bore with the screwdriver.
9.
Remove the four attaching bolts from the bearing cap
and turn the input shaft to free the bearing cap assembly
from the housing. Turn the shaft until the plunger clears
the piston.
Do not attempt to turn the shaft out
of the piston. The re-circulating balls
must be removed before the shaft can be removed.
Shaft damage will occur if it is forced out of the
piston!
CAUTION
10. Carefully slide the piston and bearing cap assembly out
of the housing to locate the ball guide retainer.
IMPORTANT: It may be necessary to rotate the piston to
locate the ball guide retainer.
CAUTION
The ball guide retainer must be held
in place when sliding the piston out
of the housing. Re-circulating balls can be lost if
the retainer is not held in place.
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11. With the piston in the housing and the ball guide retainer
visible, screw a #8 x 1.5” sheet metal screw into the hole
in the ball guide retainer.
CAUTION
Do not crack the ball guide retainer
during this operation.
12. Using a pair of pliers on the head of the screw, carefully
pry the ball guide retainer out of the piston.
13. Remove the ball return tubes from the piston. Take care
not to lose any of the re-circulating balls when removing
the ball return tubes.
14. Carefully turn the shaft to remove the re-circulating balls
from the piston. All M-Series steering gears will have
24 balls. Verify that all balls are removed before
removing the valve shaft from the piston.
15. Remove the bearing cap and shaft assembly from the
piston. Place the bearing cap and shaft assembly on a
clean work surface. If equipped with manual plungers,
remove the plunger at this time. Follow the Auto
Plunger Repair procedure in the Common Procedures
section for Auto Plunger equipped steering gears.
IMPORTANT: Do not force the shaft. The shaft will slide
freely from the piston if all 24 balls are removed.
Do Not Disassemble the bearing cap
and shaft assembly. There are no serviceable parts in this assembly. Only the input shaft
seal is serviceable! Refer to Input Shaft Seal
Replacement in “Common Procedures” section.
CAUTION
52
16. Carefully slide the piston out of the housing. Piston to
housing clearance is very tight. Do not force the piston
to remove it. Place the piston on a clean work surface.
Remove the Teflon piston ring and energizing O-ring
from the piston.
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17. Remove the seal ring and tetra-seal from the bearing cap
and shaft assembly.
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IMPORTANT: Do not dissaemble the bearing cap and shaft
assembly.
18. Remove the cylinder head from the housing. Remove the
seal ring and tetra-seal and discard. If equipped with
manual plungers, remove the plunger at this time.
Follow the Auto Plunger Repair procedure in the
Common Procedures section for Auto Plunger equipped
steering gears.
19. Remove the sector shaft oil seal from the housing.
20. Disassembly of the steering gear is complete.
IMPORTANT: Do not dissaemble the bearing cap and shaft
assembly.
IMPORTANT: Do not remove the piston plug from the piston.
53
Sub Assemblies
M-SERIES OPTIONAL INTEGRAL RELIEF VAINE
An optional integral pressure relief valve is offered with the Sheppard M-Series steering gear. The relief valve
cartridge is located in the bearing cap. The valve limits the maximum operating pressure in the steering system. In
most cases. the hydraulic supply pump will have a maximum relief pressure setting higher than the integral relief
valve in the steering gear.
When maximum relief pressures are reached in the steering system, the excess pressure is relieved within the steering
gear.
When oil pressure exceeds the maximum relief pressure setting of the pilot-operated relief valve, the valve opens.
Excess pressure is bled off into the oil return circuit through the return port of the steering gear.
The relief valve cartridge can be removed for cleaning and inspection. Remove the relief valve nut and cartridge
assembly. At this time the strainer can also be cleaned and inspected.
NOTE: The relief valve cartridge can not be disassembled and must be replaced if bad.
The O-rings and strainer are replaceable and are included as part of the complete seal kit.
CAUTION
Never use old seals or O-rings. Use the complete seal kit.
To install the relief valve cartridge in the bearing cap. insert the cartridge assembly into the relief valve bore and torque
the valve nut to 35 ft./lbs.
54
Reassembly
CLEANING & INSPECTION
Cleaning
Cleanliness is important. Dirt and foreign material that gets into the steering system during repair operations can
cause damage or a possible steering malfunction at a later date. Due to the close tolerances between mating parts it is
best to have all parts at the same temperature for reassembly.
Clean the machined parts individually to avoid damage caused by “bumping” together. Use clean solvent to wash
parts. Dry the parts with compressed air. Nicks or burrs must be removed with a fine hand stone before assembly.
Use clean lubricant to coat parts for assembly. All hoses, lines and the reservoir should be cleaned before reinstalling
a repaired steering gear or after pump replacement. Replace the filter element or cartridge.
Inspection
Make a careful visual inspection of all steering gear parts. Replace worn parts as well as any parts that show signs of
stress or fatigue.
STEERING GEARS THAT HAVE BEEN DAMAGED IN AN ACCIDENT MUST BE REPLACED.
IMPACT LOADS TRANSMITTED THROUGH THE FRONT AXLE AND STEERING LINKAGE
INTO THE STEERING GEAR CAN STRESS PARTS TO A POINT JUST SHORT OF FAILURE. FURTHER USE
IS UNSAFE AND THE STEERING GEAR ASSEMBLY AND PITMAN ARM MUST BE REPLACED. DISTORTED
PITMAN ARMS, TWISTED SECTOR SHAFTS, BROKEN OR CRACKED RACK AND PINION GEAR TEETH
ARE SOME SIGNS OF IMPACT DAMAGE. BROKEN OR DAMAGED MOUNTING BRACKETS MUST BE
REPLACED.
DANGER
Steering gear parts inspection may show problems in other areas of the steering system. To avoid repeat problems
inspect all parts carefully. Listed below are the more common problems you may see during steering gear inspection
along with their possible cause. This information should be considered carefully when repairing low mileage vehicles. Remember it is more important to repair the cause than the results.
Parts Discolored (blue)
Sector Shaft (Roller
bearing wear)
1. Operating temperatures too high
2. Steering column binding
3. Hydraulic supply pump
malfunctioning
1. Incorrect lubricant use
2. Excessive temperature
3. Overloading the axle
4. Contaminated lubricant
5. Impact damage
Actuating Shaft
(ball thread brinelled
or dented)
1. Impact damages
Actuating Shaft
(thread wear)
1. Incorrect lubricant used
2. Overloading
3. Insufficient operating pressure
4. Insufficient oil flow
5. Continued operation at high
temperature
Broken Housing
1. Accident damaged
Housing or Piston Scoring
(Also see following
NOTE)
1. Foreign material entry
2. Severe overloading
3. Incorrect lubricant used
4. Excessive temperature
(over 250)
5. Pump damaged
Thrust Bearings
(pitted, rough)
1. Foreign material in system
2. Excessive overloading
Thrust Bearings
(broken or distorted)
1. Impact damage
2. Incorrect repairs
Piston Rings (cut.
1. Incorrect installation
pinched. sheared or worn) 2. Incorrect assembly
Note on scoring
Minor scoring and scuffing of the piston and housing of the steering gear is normal. During operation at relatively
high pressure and flow rates this minor scoring will not affect the safety or operation of the steering gear. Minor scoring should be polished with a fine hand stone or crocus cloth.
CAUTION
The cylinder bore should not be honed or bored out. This will increase internal leakage.
55
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Reassembly
1.
Install a new seal on the piston by first installing the
O-ring in the groove then carefully installing the Teflon
piston seal over the O-ring. The Teflon seal will stretch
as it is fitted over the piston. Take care not to tear the
Teflon when installing. Use a ring compressor on the
Teflon seal to aid in the installation into the housing.
2.
Install a new sector shaft oil seal in the housing. When
properly fitted the seal will ride between the roller
bearing and housing lip. The black lip of the seal must
face the bearing.
IMPORTANT: The sector shaft seal is a two piece seal. It
will necessary to bend the seal for installation. Once the
seal is installed you may have to work the seal into place
with your fingers or a blunt seal pick to properly seat the seal.
Press only on the body of the seal.
DO NOT PRESS ON THE LIP OF THE SEAL!
3.
Install the piston into the steering gear housing. Refer to
the marks made at disassembly to insure you are
installing the piston in the correct end of the housing.
NOTE: The housing will have a lead in chamfer on one end
for piston installation. Piston to housing clearance is very
close. Do not force the piston when installing. Housing damage can result.
4.
Rotate the piston so the ball guide cavity is visible and
accessible as shown.
NOTE: The rack gear of the piston may not be in the proper
position for assembly during this process.
5.
Install a new seal ring and tetra-seal on the bearing cap
assembly.
NOTE: If you are working on an Auto Plunger equipped
gear, make sure you have completed the repair procedure
outlined in the Auto Plunger Repair section of this manual.
56
6.
Insert the valve shaft into the ball thread of the piston.
Align the threads of the valve shaft with the holes in the
ball guide cavity.
NOTE: When properly positioned in the piston one thread of
the valve shaft will be visible through each of the ball feed
holes in the piston.
7.
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Support the bearing cap and shaft assembly with your
hand. Install the re-circulating balls, one at a time, into
the ball guide feed hole closest to the end of the piston.
Do not allow the re-circulating balls
to drop into the rearward hole or
feed balls through both holes. Steering gear lock
up can result!
CAUTION
8.
Slowly turn the input shaft into the piston while feeding
the balls into the ball guide feed hole. As you feed the
balls you will feel the shaft being supported as the balls
fill the threads.
9.
Continue to feed the balls until the balls are visible in the
rearward hole of the ball guide cavity.
NOTE: Approximately 16 balls will have been installed when
they become visible in the rearward hole of the ball guide
cavity.
CAUTION
Do not back off the shaft during
ball installation. Binding or shaft
damage can result.
10. Hold the shaft assembly stationary and install both
halves of the ball return tube. Continue feeding the balls
through the access hole in the ball return tubes until 24
balls have been installed.
NOTE: Twenty four balls must be installed for proper
operation.
57
11. Replace the O-ring on the ball guide retainer and install
the ball guide retainer over the ball return tubes.
IMPORTANT: When properly installed the ball guide retainer
will be flush with the contour of the piston.
12. Slide the piston into the housing until the ball guide
retainer is secured by the housing. Locate the rack gear
of the piston with the opening in the housing at this
point.
13. Slide the piston into the housing until the rack gear is
centered in the sector shaft bore of the housing. Locate
the timing marks on the piston rack for reference.
TAKE CARE WHEN INSTALLING
THE PISTON INTO THE HOUSING.
DO NOT PINCH OR TEAR THE PISTON RING DURING
INSTALLATION.
WARNING
14. Align the marks on the bearing cap with the marks on
the housing. Install the four attaching bolts in the
bearing cap assembly and torque to specifications.
IMPORTANT: Some M-Series steering gears use different
length bolts in the bearing cap attachment. Make sure the
bolts do not bottom out when installed.
15. Install the sector shaft by carefully aligning the timing
mark of the sector shaft with the two timing marks of the
rack piston. It will be necessary to tap the sector shaft
into place with a soft hammer to ensure full rack
engagement.
IMPORTANT: Coat the end of the sector shaft with clean
chassis grease to prevent seal damage at installation.
58
16. Install a new sector shaft oil seal in the sector shaft
cover. When properly fitted the seal will ride between the
roller bearing and cover. The black lip of the seal must
face the bearing.
IMPORTANT: The sector shaft seal is a two piece seal. It
will necessary to bend the seal for installation. Once the seal
is installed you may have to work the seal into place with
your fingers or a blunt seal pick to properly seat the seal.
Press only on the body of the seal. DO NOT PRESS ON
THE LIP OF THE SEAL!
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NOTE: There are three styles of sector shaft covers used on
Sheppard M-Series steering gears. Seal installation is the
same for all cover styles.
17. Install the sector shaft cover onto the steering gear. It
may be necessary to drive the cover on with a dead blow
hammer. Attach the cover using the appropriate tools for
the steering gear you are working on.
IMPORTANT: Coat the seal area of the sector shaft with
grease to prevent seal damage at installation.
When installing a snap ring or clip
style cover, the cover must be flush
or below the groove in the housing. Improper
installation can result in separation of the cover
without warning. Personal injury or an accident
can result.
CAUTION
VARIATION: Some Sheppard M-Series steering gears may
have a closed end sector shaft cover. When installing a
closed end cover, be sure to install the protective plug in the
cover after installation.
If your closed end cover has a vent hole, make sure the vent
hole is open before installation of the cover. After the cover
is installed, plug the vent hole with an RTV compound to
avoid ingestion of contaminants.
59
18. Install a new seal ring and tetra-seal on the cylinder head
end cap. Install the cylinder head onto the housing,
taking care to align the marks made at disassembly.
Torque the attaching bolts to specifications.
NOTE: If you are working on an Auto Plunger equipped gear,
make sure you have completed the repair procedure outlined
in the Auto Plunger Repair section of this manual.
19. Replace the O-rings on manually adjustable plungers and
install them into the end caps.
IMPORTANT: The longer plunger will be installed in the
bearing cap end of the steering gear.
20. Install the excluder seal in the sector shaft cover using a
2.25” seal driver. Pack the lip of the excluder seal with
clean chassis grease before installing. When properly
installed the lip of the excluder will face outward and the
seal will bottom in the excluder seal groove.
21. Install the frame side dust cover on housing. Thoroughly
clean the housing with a suitable solvent and apply a
bead of RTV on the edge of the disk to secure it to the
housing. Allow adequate time for the RTV to set.
22. Install the snap ring protective cover in the sector shaft
cover bore over the snap-ring by lightly tapping on the
outside diameter. Install the slide on V-boot over the
sector shaft. Install the rubber boot on the input shaft.
The steering gear may now be installed on the vehicle. Refer
to the Common Procedures section for pitman arm installation,
relief plunger adjustment and bleeding procedures
60
Dual Steering Gear Systems
Two or more integral steering gears are sometimes used where front axle weights exceed 16,000lbs gross front axle
weight rating. Dual steering systems are used to balance the steering gear output across two or more steering arms
and conserve under hood space.
The secondary or slave unit is mounted on the right hand side of the vehicle and operates off of pressure supplied by
the master or left hand steering gear. Dual steering systems are mechanically linked to the front end components by a
drag link and steer arm on the right hand spindle on the axle. No physical link exists between the master and slave.
Hydraulic pressure and flow reacting on the slave gear piston causes the slave gear to operate under pressure in the
opposite direction of the master gear assisting in the power steering operation of the system. Hydraulic relief
plungers are not used in the slave gear. Master gear relief plungers will relieve hydraulic pressure for both gears
when properly adjusted.
There are three dual system configurations common with the Sheppard M-Series steering gears M-Series Cooling
Slave, M-Series Standard Slave and 92 series slave gears. Operation of the slave is consistent no matter which slave
configuration you are working with.
Dual systems can be plumbed one of two ways depending on slave gear configuration. Typical plumbing
configurations are:
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M-Series Cooling Slave - Cooling slaves have a low pressure return port cast along the length of the slave gear
housing. Return oil from the master gear is routed through this port and back to the reservoir. The additional line
provides a cooling effect as well as using the slave gear as a heat sink.
92 Series Slave Gear - Return oil is routed from the return side of the master gear through the sector shaft bore of
the 92 series slave then back to the reservoir. The additional line provides a cooling effect as well as using the slave
gear as a heat sink. Refer to page 63 for diagram
M-series Standard Slave - Requires only the cross over pressure lines between the master gear and the slave
steering gear. No additional line is required in the plumbing of the standard slave dual system. Refer to page 62
for diagram
NOTE: The Sheppard M-Series steering gear may also be used with an assist cylinder. Refer to your truck
manufacturer’s service manual for operation, bleeding and repair procedures for hydraulic assist cylinders.
IMPORTANT: Bleeding of the dual system is critical whenever the oil has been changed, the system has been opened
to atmosphere or a steering gear has been replaced. Follow the Dual System Bleed procedure in the Common
Procedures section of this manual.
61
Standard Slave System
62
Cooling Slave System
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M-Series Slave Gears - Cooling Slave & Standard Slave
The Sheppard M-Series slave gear is simple in operation and should not require disassembly for repair.
Sheppard M-Series slave gears contain only two moving parts, a power piston and a sector shaft. Repairs can be
completed, if necessary, by following the procedures in the disassembly & reassembly sections of this manual. Keep
in mind that slave steering gears do not have input shafts or relief plungers should you have a need for disassembly.
Typical M-Series Cooling Slave Gear
Typical M-Series Standard Slave Gear
Typical 92 Series Slave Gear
Disassembled Slave Steering Gear - M-Series.
Refer to Sheppard Service Manual 1000485 for 92
Series Slave repairs.
64
Final Adjustments
Sheppard Power Steering gears have no external adjustments for sector shaft or valve shaft pre-load. Make sure all
linkages and system components are within vehicle manufacturers specs.
TORQUE: Check all fastener torques when installing the steering gear. A torque chart for steering gear fasteners can
be found in the chart below. Consult the vehicle manufacturers service manual for steering gear to frame, pinch bolt
and drag link torque values.
PITMAN ARM: Pitman arm application torque is critical. Follow the pitman arm installation instructions in this
manual.
DANGER
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IMPROPER INSTALLATION OF THE PITMAN ARM COULD LEAD TO AN ACCIDENT OR
SERIOUS PERSONAL INJURY!
SET RELIEF PLUNGERS: Verify the type of relief plungers in your steering gear. Refer to the Common Procedures
section of this manual to properly set the relief plungers.
BLEED THE SYSTEM: Follow the guidelines in the Common Procedures Section for proper bleeding of both single
and dual gear systems.
TORQUE SPECIFICATIONS
APPLICATION
Bearing Cap Cover - All M-Series
Bearing Cap Bolts
M80
M90
M100
M110
Cylinder Head
M80
M90
M100
M110
All Clip Style Cover Bolts
SIZE
M10 x 1.5
GRADE
10.9
FT/LBS
53-64
(Nm)
(72-87)
M10 x 1.5
M12 x 1.75
M14 x 2.0
M16 x 2.0
10.9
8.8
8.8
10.9
53-64
72-87
114-140
230-277
(72-87)
(97-118)
(154-190)
(312-376)
M10 x 1.5
M12 x 1.75
M14 x 2.0
M10 x 1.5
M8 x 1.25
10.9
8.8
8.8
10.9
12.9
53-64
72-87
114-124
53-64
31-38
(72-87)
(97-118)
(154-190)
(72-87)
(42-52)
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TROUBLESHOOTING CHECKLIST
Before proceeding with the following tests, be sure to read the diagnosis and Troubleshooting section of this manual.
Check all mechanical and external conditions before hydraulic testing.
Date: ________________
Servicing Dealer Location:
Customer Name:
___________________________________
___________________________________
___________________________________
___________________________________
Description of Steering Complaint:
_______________________________________________________________________________________________
_______________________________________________________________________________________________
____________________________________________
Vehicle Model ____________________________
Steering Gear Model:_______________________
Slave Gear Model (if equipped) ______________
Pump Manufacturer ________________________
Mileage_____________VIN_____________
Serial No._________________________
Serial No. _________________________
Front Axle Weight __________________
Hydraulic Tests:
Do not remove the steering gear! Install a pressure and flow tester in series with the pressure line of the pump as outlined in the Diagnosis and Troubleshooting Section. Record the following information:
Stabilized Oil Temperature: _________
System Backpressure @ Idle ___________ Backpressure @ Full RPM ___________
Maximum System Pressure (Pump Relief Setting) ______________psi
Flow @ Idle with Backpressure Only .................................... ____________GPM
Flow @ Full Governed RPM Backpressure Only ................_____________GPM
Flow @ Idle With 1500psi Load Applied .............................._____________GPM
Flow @ Full Governed RPM With 1500psi Load Applied .._____________GPM
Static Steer Pressure
Static Steer Input
Right Turn_________psi
Left Turn_________psi
Right Turn ________In. Lbs Left Turn_________In. Lbs.
If you are unsure of your diagnosis contact Sheppard Field Service at 1-800-274-7437
R.H. Sheppard Company, Inc.
101 Philadelphia Street, P.O. Box 877 • Hanover, PA 17331-0877 • Tel: 717.637.3751 • Fax: 717.633.4125
www.rhsheppard.com
RHSCO1202000
66
Heavy Duty Power Steering Test Kit
This tester is a self contained, direct reading device to check system flow, pressure or both simultaneously. Requiring no electrical connections, it can detect worn components, verify fllow and pressure control settings or monitor
overall performance.
EASY TO USE Only one hose connection is broken, either at the
pump output or at the pressure input to the power
steering gear housing.
• Installs between pump and steering gear
• Shutoff valve isolates pump from gear
• Pressre and flow can be read simultaneously
• 0-3000 P.S.I. pressure guage
• 1-10 G.P.M. flow meter
• Complete with hoses & standard swivel fitting
• SHIPMENT FROM STOCK
• INCLUDES SHEPPARD SERVICE MANUAL
PHOTOCOPY AND USE FOR ORDER FORM
CUSTOMER’S ORDER NO.
DATE
SOLD TO:
ITEM
NO.
OUR ORDER NO.
SHIPPED TO:
QTY
ORDERED
PART
NUMJBER
PART
DESCRIPTION
5517641
Pressure Flow & Test Kit
UNIT
PRICE
TOTAL
Includes Sheppard service manual with operating instructions
R.H. Sheppard Company, Inc.
101 Philadelphia Street, P.O. Box 877 • Hanover, PA 17331-0877 • Tel: 717.637.3751 • Fax: 717.633.4125
www.rhsheppard.com
67
From:
Name ____________________________________________
Address __________________________________________
City _________________ State _______ Zip
__________
R.H. Sheppard Company, Inc.
P.O. Box 877
101 Philadelphia Street
Hanover, PA 17331-0877
Attn: Customer Service
68
Place
Stamp
Here
R.H. Sheppard Company, Inc.
101 Philadelphia St.
P.O. Box 877
Hanover, PA 17331-0877
tel: 717.637.3751
fax: 717.633.4125
www.rhsheppard.com